Pipe covering



Jan. 24y 1933. o. F. MOTTWEILER 1,895,420

PIPE COVERING Filed Sept. 26, 1930 Patented 24, 1933 UNITED STATES PATENT OFFICE OLIVER F. MOTTWEILER, OFALEXANDRIA, INDIANA, ASSIGNOR TO GENERAL INSULATING AND MANUFACTURING COMPANY, F ALEXANDRIA, INDIANA PIPE COVERING Application led September 26, 1930. Serial No. 484,502.

The general object of this invention is to provide a novel non-conducting pipe covering the body, or insulating material of which shall be composed of mineral wool.

By the term imineral wool I include shredded material made either from molten slag or molten rock. The former is sometime'referred to as slag Wool, and the latter as rock wool.

The invention resides in a novel method of producing the pipe covering as well as in the covering itself.

The invention is characterized, by a shell or casing consisting of two semi-cylindrical members hinged together along one edge and each half of the shell or casing containing a lling of mineral` wool which is shaped to conform to the curvature of the pipe to be covered, and of the desired thickness to produce the required degree of heat insulation, the covering being applied to the pipe to be covered by simply opening the two halves of the shell and placing them over the pipe and then bringing the two halves of the shell together. The usual means for securing the covering on the pipe are then employed.

The method involved consists, primarily, in forming sheets or slabs of mineral wool of uniform thickness and in compact form,

placing a section of such sheet or slab in each of two semi-cylindrical shells, positioning a cylindrical mandrel, or former, to extend centrally and longitudinall of one of the shell members, and then c osing the other half of the shell over said mandrel whereb the mineral woolin each half of the shell wi l be provided with a central, longitudinal,

semi-cylindrical groove, due to the fact that the mineral wool will yield to conform to the curvature of the mandrel and will be to a great extent permanently compressed.

As a subsidiary feature of the method, the

mandrel, after the shell has been closed about` it to compress the mineral wool thereover, is turned or rotated several times to more exactly shape the grooves in the mineral wool, to impart a smooth surface thereto and to assist in giving a permanent shape to said grooves. Owing to the springy nature of the mineral wool, which it may be stated, approximates the conditlon of ordinary raw cotton, when the two halves of the pipe covering are closed about a pipe, the mineral wool will be pressed rmly against the pipe throughout the length of the covering and thus avoid the possibility of spaces or channels being formed between the covering and the outer surface of the pipe which, so far as I am aware, is an objection incident to all commercial pipe coverings manufactured prior to my invention.`

After forming the grooves in the mineral wool as above described, the mandrel is removed and a temporary mandrel or former in the shape of a card board tube, or a tube of similar cheap material is substituted for the mandrel and the two halves of the casing temporarily secured about the same, so that in shipment the mineral wool will be prevented from becoming dislodged, and the true form of the grooves will be preserved.

There are several other features characteristic of the invention as a whole, and of the method of producing the same, but these will be more clearly understood from the detailed description to follow.

The invention, and the steps employed in its production are illustrated in the accompanying drawing in ywhich Fig. l is a view in elevation of a section of my improved pipe covering, a portion thereof being broken away at one end to better illustrate the construction;

Fig. 2 is a cross sectional view on an enlarged scale taken on the line 2-2 of Fig. l;

Fig. 3 is a perspective View of the shell or casing separated at one side, and in readiness to have a mineral wool filling inserted in each half of the shell;

Fig. 4 is a cross sectional View on an enlarged scale showing the two halves of the shell or casing supplied with the mineral wool filling; n

Fig. 5 is a view in end elevation on the same scale .as Fig. 4 showing in full lines the two halves of the shell or casing brought together about a cylindrical mandrel centrally positioned by means of temporary guides, and in dotted lines showing the upper half of the shell or casing in an elevated position; Fig. 6 is a broken, central, longitudinal sectional view of the parts shown in Fig. 5,

the view being on a somewhat larger scale, and illustrating particularly the manner of positioning the mandrel in one of the memers of the shell or casing; and

Fig. 7 is a broken perspective view showing a section of a relatively thick sheet or slab of mineral wool provided at intervals with rows of stitching to hold the material in place and prevent parts of it from falling out when handling or applying the covering about a pipe.

Referring now to the drawing, the numeral 1 indicates a shell or casing, which is usually made of fibre board or card-board, treated with a suitable material, such as silicate of soda to give it hardness and rigidity. If the ipe covering is to be placed on pipes subected to Weather conditions, the shell or casmg may be treated with asphalt and coated with shellac, for the same purpose, and also to render it water-proof.

The casing 1 is formed as a tube and then cut longitudinally from end to end on a right line, and preferably the corresponding opposite side of the tubeis scored along a line 2, as indicated in Fig. 3, in order that the two halves of the casing may be bent outward on each other as a hinge.

For the purpose of providing the mineral Wool filling, I first form a slab or sheet of mineral wool of the desired thickness and of relatively compact character, such as indicated by the numeral 3 of Fig. 7. Preferably, the mineral wool is compacted and placed in sheet form according to the apparatus and method described in my pending ap- 40 plication, Serial No. 469,074, filed July 19,

1930. If the slab or sheet of mineral wool is quite thick, say, four or live inches thick, it

may be stitchedwith asbestos string or wire, as indicated at 4 in Fig. 7, in order that the I5 material may be held in place and prevented from falling out when handling or applying the covering around a pipe. The sheet of mineral wool having been formed, a section thereof slightly longer than the shell 1, and of a width to cause its side edges, when a section of the sheet mineral wool is placed in each half of the shell 1, to project slightly above the opposite side edges thereof, is then cut from the sheet. The interiors of the two halves 5, 6, of the casin 1 are first coated with cement or glue as indicated at a, and a section of the sheet mineral wool is bent upon itself longitudinally and inserted into each half of the casing, as illustrated in Fig. 4, in which the numerals 7 and 8 indicate, re-

spectively, the mineral wool fillings in the casing members 5 and 6. The under surface of the mineral wool will, of course', adhere to the glue or cement and will be held thereby to`-the casing. sections 5, 6.

It is next necessary to form a longitudinal groove centrally of eachof the fillings 7 and 8, which grooves are adapted to embrace the pipe ultimately to be covered. To this end, IA

employ a mandrel 9, Figs. 5 and 6, which may be a section of pipe of the diameter of the pipe for which the covering is intended and sonicwhat longer than the casing 1. In order that the mineral wool may be of uniform thickness at al1 points around the pipe covered, it is desirable to center the mandrel 9 relative Yto the section 5 or 6 of the casing 1 in which it is positioned. This may be conveniently done by providing for one half of each shell to be filled, a semi-circular guide 10, having o'n its straight side a central, semi-circular recess 11, adapted to receive the mandrel 9 and provided with clips 12 adapted to embrace the sides and bottom of the section of the casing to which it is applied, said clips being preferably shouldered, as indicated at 13, to maintain the guides 10 at some distance from the end of the casing section, in order that the mineral Wool filling may be permitted to project beyond the end of the casing section, as indicated, with reference to the filling 8, at 14, in Fig. 6. As shown in Fi 4, the opposite side edges of the fillingsg and 8 will also project above the opposite side edges of the respective casing sections 5 and 6, as indicated at 15 in said Fig. 4. With a guide 10 applied to each end of a casing section, the mandrel 9 is then centered relative thereto by being inserted in 'the recesses 11. As shown in Fig. 6, this centering of the mandrel has been performed in the casing section 6. With the mandrel in place the casingsection 5, with its mineral wool filling, is then turned over or about the mandrel, in the manner indicated by the dotted 'and full lines in Fig. 5, and this results in compressing or compacting the mineral wool about the mandrel and formin a central longitudinal groove in each of the llin 7 and 8. As shown by Fi'gf, the mandre projects "beyond the guide 10, formin a handle portion 16, and` this may be graspe by the operator at one or both ends and rotated, or turned back and forth a number of times, in order to impart a smooth surface to the walls of the grooves formed in the mineral wool fillings, and to render said grooves more nearly permanent in character. In Fig. 5, I have indicated the groove formed in the filling 7, by the numeral 17. After the above o eration, the guides .10 are removed, the section 5 turned back to the position indicated in Fi 4, and the mandrel 9 removed. A tube 18, w ich may conveniently be of cardboard or other similar cheap material, and o f the length of casing 1, is then substituted for the mandrel, and the two sections closed about the same as indicated at Fig. 2. The casing 1 is next covered with a sheet of suitable material 19, such as waterroof or fire-proof paper, or the like, which is glued to the outside thereof, beginning at one edge of one of the casing sections and continuing around to the meetin edge of the other casing section, leaving a a 20 to extend beyond the meeting edges o the sections which, when the covering is applied to the pipe, will be glued to the portion of itself on the other section which 1t overlaps, in order to firmly secure the two sections together. Metal bands 21, of conventional construction, may also be applied about the canvas covering for securely holding the two sections 5 and 6 together.

If desired, a conventional molded casing, hinged together by the covering of canvas, or the like, could be used for casing 1.

Froin an inspection of Fig. 1, it will'be seen that the canvas covering or jacket 19, projects beyond one end of the shell 1, as indicated at 22. This is for the purpose of enabling thispart of the jacket to be glued around the end of the next section of pipe covering, the end of which will be caused to abut against the end of the preceding section.

I have described, and in Figs. 4 and 6 have shown, the mine-ral wool fillings 7v and 8 as projecting above and beyond the ends of the respective sections of 5 and 6 in which they are placed. By so doing, when section 5 is closed down upon section .6, the upper surfaces of the fillings at either side 'of the central grooves, will come in contact and be pressed together so as to make a practically continuous insulating body, as shown by Fig. 2. In other words, no joint between the two fillings 7 and 8 will be apparent.

In the same manner, when one section of pipe covering is caused to abut against a preceding section, the projecting portion 14 of the filling will be pressed into contact with the corresponding projecting portion of the filling of said preceding section, the mineral wool of the two sections being thus compressed and caused to commingle or intermix, so that no joint will appear between adja- 'cent sections.

Thus, a pipe having my improved pipe covering applied will be surrounded by a/ circular body of isula-ting material of uniform thickness and continuous circumferentially and from end to end of the pipe. In addition, because of the springy character of the mineral wool, the circular filling thereof within the casing 1 will maintain at all times close contact with the pipe which it surrounds. Another advantage incident to my invention is the fact that, the mineral wool having been placed in compact form by means of pressure rollers, according to the invention of m prior application previously alluded to, t ere is no danger of the filling settling and leaving air spaces between the pipe and the filling at the bottom of the pipe, or between the acket or casing 1, and the filling at the top of the pipe. e

I have heretofore filed applications for patents covering the treatment of mineral wool with heavy oils, or with oil having paraffine added thereto. Whenthe pipe covering, as described above, is made from this treated wool, the latter, when fabricated to the proper thickness, will stay in place in the casing without additional supports.

When untreated, or perfectly dry mineral wool is employed as a filling, it may be held in place, that is, falling out of the mineral wool,

can-be prevented, by spraying the same with high temperature glue or cement. This spraying of the mineral wool can be carried out to an extent sufficient to hold the material in shape Without in the least decreasing the efficiency of the filling as to its non-conducting properties.

From the foregoing it will be seen that I am able'to produce a thoroughly effective pipe covering, at a greatly reduced cost as cpmpared wlth the standard molded magnesia pipe coverings now generally employed. y

Furthermore, by fabricating the mineral wool, either treated or untreated, into true blanket or sheet form and fitting it into an outer shell or casing, I thereby form a practical pipe covering which can be readily stocked as a standard material for all classes of work, as the pipe coverings can be made in all sizes and in any length.

I claim:

1. The method of producing a non-conducting pipe covering which consists in fitting into each of two semi-cylindrical casing sections a filling of mineral wool of the thickness of the insulation desired, andv then closing the two casing sections over a cylindrical mandrel of the diameter of the pipe to be covered and positioned `centrally and longitudinally of said casing sections, whereby to compress the mineral wool in each casing section and form a semi-cylindrical groove in each filling.

2. The method of producing a non-conducting pipe covering which consists in fitting into each of two semi-cylindrical casing sections a sheet of compressed mineral wool of the thickness of the insulation desired, and then closing the two casing sections over a cylindrical mandrel of the diameter of the pipe to be covered and positioned centrally and longitudinally of said casing sections, whereby to compress the mineral wool in each casing section about said mandrel and form a semicylindrical groove in each filling.

3. The method of producing a non-conducting pipe covering which consists in fitting into each of two semi-cylindrical casing sections a filling of mineral wool of the thickness of the insulation desired, then closing the two casing sections over a cylindrical mandrel of the diameter of the pipe to be covered and positioned centrally and longitudinally of said casing sections, whereby to compress the mineral wool in each casing section about said mandrel and form a semicylindrical groove in each filling, and then rotating said mandrelc to impart a. smooth character and substantially permanent shape to the walls of said grooves. Y

4. The method of producing a non-conducting pipe covering which consists in coating the insides of two semi-cylindrical casing sections with an adhesive, fitting into each of said casing sections a slab of compressed mineral Wool of the thickness of the insulation desired, and then closing the two casing sections over a cylindrical mandrel of the diameter of the pipe to be covered and positioned centrally and longitudinally of saidcasing sections, whereby to compress the mineral wool in each casing section about said mandrel and form a semi-cylindrical groove in each lling.

5. The method of producing a non-conducting pipe covcring which consists in fitting into each of two semi-cylindrical casing sections a slab of compressed mineral wool to form a filling of the thickness of the insulation desired, then closing the two casing sections over a cylindrical mandrel of the diameter of the pipe to be covered and positioned centrally and longitudinally of said casing sections, whereby to compress the mineral Wool in each casing section about said mandrel and form a semi-cylindrical groove in each filling, separating said casing sections and removing the mandrel, and then spraying the outer surfaces of said grooved fillings with a high temperature adhesive.

The method of producing a non-conducting pipe covering which consists in fitting into each of two semi-cylindrical casing sections a slab of mineral Wool to form a filling of the thickness of the insulation desired, and of a width and length to cause its side edges and ends to project above and beyond the side edges and ends, respectively, of said casing sections, and then closing the two casing sections over a cylindricalmandrel of the diameter of the pipe to be covered and positioned centrally and longitudinally of said casing members, whereby to compress the mineral Wool about said mandrel and form a semi-cylindrical groove in each filling. l

7. The method of producing a non-conducting pipe covering which consists in hinging together the edges of two semi-cylindrical casing members, fitting into each of said casing members a slab of mineral Wool to form a filling of the thickness of the insulation desired, and of a width and length to cause its side edges and endsto project above and beyond the side edges and ends, respectively, of said casing members, and then closing the two casing members over a cylindrical mandrel of the diameter of the pipe to be covered and positioned centrally and longitudinally of said casing members, whereby to compress the mineral wool about said mandrel and form a semi-cylindrical groove in each filling.

8. A non-conducting pipe covering comprising two semi-cylindrical casing sections each of which is provided with a filling of compressed mineral wool having a central, semi-cylindrical substantially permanent groove extending from end to end of the filling, the outer grooved face of each filling being entirely exposed.

9. A non-conducting pipe covering comprising two semi-cylindrical casing sections hinged together at one side andeach of which is provided with a filling of compressed mineral wool having a central, semi-cylindrical substantially permanent groove extending from end to end of the lling, the outer grooved face of each filling being entirely exposed.

l0. A non-conducting pipe covering section, comprising two semi-cylindrical casing members hinged together at one side and each of which has fitted and secured therein a slab of compressed mineral wool of a width and length to project above and beyond the sides and ends, respectively, of said casing members and each of which slabs is provided with a central, semi-cylindrical groove extending from end to end thereof.

11. A stock, non-conducting pipe covering section comprising two semi-cylindrical casing members hinged together at one side and provided with a covering of canvas projecting beyond one end of the casing members and affording a flap projecting beyond one edge of one of the casing members, each of said casin members having a slab -of mineral wool tted and secured therein and provided with a central, semi-cylindrical groove extending longitudinally ofthe slab from end to end thereof, and being entirely exposed on its grooved face and the two casing members being temporarily secured about a removable tubular core of the diameter of the bore formed by said grooves when the two casing members are brought together.

In testimony whereof, I have hereunto set m hand. l

y OLIVER F. MOTTWEILER. 

